drm/i915: Fix display pixel format handling

Fix support for all RGB/BGR pixel formats (except the 16:16:16:16 float
format).

Fix intel_init_framebuffer() to match hardware and driver limitations:
* RGB332 is not supported at all
* CI8 is supported
* XRGB1555 & co. are supported on Gen3 and earlier
* XRGB210101010 & co. are supported from Gen4 onwards
* BGR formats are supported from Gen4 onwards
* YUV formats are supported from Gen5 onwards (driver limitation)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0514823..d4520d5 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3009,12 +3009,19 @@
 #define   DISPPLANE_GAMMA_ENABLE		(1<<30)
 #define   DISPPLANE_GAMMA_DISABLE		0
 #define   DISPPLANE_PIXFORMAT_MASK		(0xf<<26)
+#define   DISPPLANE_YUV422			(0x0<<26)
 #define   DISPPLANE_8BPP			(0x2<<26)
-#define   DISPPLANE_15_16BPP			(0x4<<26)
-#define   DISPPLANE_16BPP			(0x5<<26)
-#define   DISPPLANE_32BPP_NO_ALPHA		(0x6<<26)
-#define   DISPPLANE_32BPP			(0x7<<26)
-#define   DISPPLANE_32BPP_30BIT_NO_ALPHA	(0xa<<26)
+#define   DISPPLANE_BGRA555			(0x3<<26)
+#define   DISPPLANE_BGRX555			(0x4<<26)
+#define   DISPPLANE_BGRX565			(0x5<<26)
+#define   DISPPLANE_BGRX888			(0x6<<26)
+#define   DISPPLANE_BGRA888			(0x7<<26)
+#define   DISPPLANE_RGBX101010			(0x8<<26)
+#define   DISPPLANE_RGBA101010			(0x9<<26)
+#define   DISPPLANE_BGRX101010			(0xa<<26)
+#define   DISPPLANE_RGBX161616			(0xc<<26)
+#define   DISPPLANE_RGBX888			(0xe<<26)
+#define   DISPPLANE_RGBA888			(0xf<<26)
 #define   DISPPLANE_STEREO_ENABLE		(1<<25)
 #define   DISPPLANE_STEREO_DISABLE		0
 #define   DISPPLANE_SEL_PIPE_SHIFT		24